Getting there is half the fun, but it's also part of the conundrum facing modern travelers. Namely, how can you get to the places you need or want to go without having an undue negative impact on the environment? The answer is green travel, which, according to Mullis, "means to focus on limiting your negative impact and improving your positive impact."

In the old sense, green travel means visiting locales noted for environmental charm. Ecotourism may take you to a tent resort in the rain forest, or to a floating hotel that has been towed to a summertime location on a Canadian lake to avoid affecting the environment to the same degree that a permanent, year-round facility does. This kind of green travel is enjoyable and in demand, and while it helps remind travelers of the beauty and pleasure of un- spoiled locations, it doesn't necessarily help reduce the browning impact of our non-vacation, day-to-day living.

The new green travel tackles that issue. Basically, the new take on the concept is to travel in a way that minimizes your environmental impact. Organizations such as Sustainable Travel International offer a lot of guidance on how to do that; for example, you can stay at hotels that recycle wastewater, and you can use public transportation when it's available in the cities you're visiting. Mullis suggests asking whether an organization has a sustainability policy, trains its staff in sustainable travel, and practices recycling.

Carbon offsets play a big role in this kind of green travel, with some online ticket sellers offering easy ways to purchase carbon offsets at the same time you book a flight, hotel room, or car rental. But air travel probably gets more attention than it deserves, says Arnold. While flying does have an impact, especially with regard to carbon emissions, it does not have nearly the negative effect that other carbon contributors do. For instance, he considers coal-fi red electricity-generating plants a much more serious problem. "Aviation is a minor part," Arnold says. "For certain travelers, it's an issue, but globally, it's only about 2 percent of the problem."

Cost-to-coast and downtown to uptown, you can find a place to rest your head that will support your green ideals. These hotels are among hundreds that belong to the Green Hotels Association, a Houston, Texas organization that recogizes lodgings that have made efforts to conserve water, energy, and solid waste.